Device and method for detecting current-carrying contact performance of sleeve

Abstract

The invention discloses a device and method for detecting current-carrying contact performance of a bushing, and relates to the technical field of electrical equipment monitoring, and the device comprises an AC excitation power supply which is used for generating an excitation signal; the current booster is used for amplifying the excitation signal generated by the alternating current excitation power supply; the casing oil end detection device is used for detecting the vibration condition of the casing oil end to obtain a first detection signal; the sleeve air end detection device is used for detecting the vibration condition of the sleeve air end to obtain a second detection signal; and the measurement and control terminal is used for receiving the first detection signal and the second detection signal and analyzing the first detection signal and the second detection signal to judge the running state of the sleeve. Through the frequency doubling excitation vibration test method, small faults such as bending of the sleeve, distortion of the wiring terminal and poor contact of the elastic current-carrying terminal can be detected, the detection precision is greatly improved, and safe and stable operation of a power system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment monitoring, and specifically to a detection device and method for the current-carrying contact performance of a bushing, which are used to detect the operating state of the bushing and its elastic current-carrying terminal. Background Art

[0002] In the power system, as a key device, the operating state of the bushing directly affects the safety and stability of the system.

[0003] Traditional bushing detection methods have problems such as low detection accuracy, inability to monitor in real time, and difficulty in discovering potential minor faults. For example, for the poor contact of the elastic current-carrying terminal inside the bushing, it is very difficult for the existing technology to accurately detect it in the early stage. Once the fault develops, it may lead to serious power accidents and cause huge economic losses.

[0004] Therefore, it is of great practical significance to develop an efficient and accurate bushing detection technology. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies in the existing technology, and design a detection device and method for the current-carrying contact performance of a bushing to realize real-time monitoring of the operating state of the bushing, timely discover potential fault hazards, avoid the further development of faults, and ensure the safe and stable operation of the power system.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0007] In a first aspect, the present invention provides a detection device for the current-carrying contact performance of a bushing, including:

[0008] An AC excitation power supply for generating an excitation signal;

[0009] An up-current transformer for amplifying the excitation signal generated by the AC excitation power supply;

[0010] A bushing oil-end detection device for detecting the vibration condition of the bushing oil end to obtain a first detection signal;

[0011] A bushing air-end detection device for detecting the vibration condition of the bushing air end to obtain a second detection signal;

[0012] A measurement and control terminal for receiving the first detection signal and the second detection signal, and judging the operating state of the bushing by analyzing the first detection signal and the second detection signal;

[0013] The output terminal of the AC excitation power supply is connected to a current booster, the output terminal of the current booster is connected to a bushing oil-end detection device and a bushing air-end detection device, and the output terminals of the bushing oil-end detection device and the bushing air-end detection device are connected to a measurement and control terminal.

[0014] As a further technical solution of the present invention, the bushing oil-end detection device includes:

[0015] A bushing oil-end current-carrying terminal, which is arranged at the oil end of the bushing current-carrying conductor and connected to the oil end of the bushing current-carrying conductor;

[0016] A bushing oil-end elastic current-carrying terminal, which is arranged between the oil end of the bushing current-carrying conductor and the bushing oil-end current-carrying terminal and connected to the bushing oil-end current-carrying terminal, and is used to generate mechanical vibration;

[0017] A first vibration sensor, which is arranged on the first flange at the oil end of the bushing current-carrying conductor and used to detect the mechanical vibration generated by the bushing oil-end elastic current-carrying terminal;

[0018] The output terminal of the first vibration sensor is connected to the measurement and control terminal, and the bushing oil-end current-carrying terminal is connected to the output terminal of the current booster.

[0019] As a further technical solution of the present invention, the bushing air-end detection device includes:

[0020] A bushing air-end current-carrying terminal, which is arranged at the air end of the bushing current-carrying conductor and connected to the air end of the bushing current-carrying conductor;

[0021] A bushing air-end elastic current-carrying terminal, which is arranged between the air end of the bushing current-carrying conductor and the bushing air-end current-carrying terminal and connected to the bushing air-end current-carrying terminal, and is used to generate mechanical vibration;

[0022] A second vibration sensor, which is arranged on the second flange at the air end of the bushing current-carrying conductor and used to detect the mechanical vibration generated by the bushing air-end elastic current-carrying terminal;

[0023] The output terminal of the second vibration sensor is connected to the measurement and control terminal, and the bushing air-end current-carrying terminal is connected to the output terminal of the current booster.

[0024] Further, the current booster is used to amplify the excitation voltage generated by the AC variable-frequency power supply by 100 to 10,000 times, with a turns ratio of 220:5 and a 1-hour thermal stable current of 3000 A. The heat dissipation method of the current booster is liquid immersion or dry type.

[0025] Further, the AC variable-frequency power supply is used to generate a variable-frequency excitation signal of 50 Hz - 1000 Hz, with a rated output power of 1600 VA and a 1-hour thermal stable current of 3000 A. The heat dissipation method of the AC variable-frequency power supply is liquid immersion or dry type.

[0026] In a second aspect, the present invention further provides a method for detecting the current-carrying contact performance of a bushing, comprising the following steps:

[0027] An AC excitation power supply generates an excitation signal;

[0028] A current booster amplifies the excitation signal generated by the AC excitation power supply;

[0029] A bushing oil-end detection device detects the vibration condition of the bushing oil end to obtain a first detection signal;

[0030] A bushing air-end detection device detects the vibration condition of the bushing air end to obtain a second detection signal;

[0031] A measurement and control terminal receives the first detection signal and the second detection signal, and judges the operating state of the bushing by analyzing the first detection signal and the second detection signal.

[0032] As a further technical solution of the present invention, the bushing oil-end detection device detects the vibration condition of the bushing oil end to obtain a first detection signal; specifically:

[0033] The current booster provides current for a bushing oil-end current-carrying terminal arranged at the oil end of the bushing current-carrying conductor;

[0034] A bushing oil-end elastic current-carrying terminal arranged between the oil end of the bushing current-carrying conductor and the bushing oil-end current-carrying terminal generates mechanical vibration under the action of the current of the bushing oil-end current-carrying terminal;

[0035] A first vibration sensor arranged on a first flange at the oil end of the bushing current-carrying conductor detects the mechanical vibration generated by the bushing oil-end elastic current-carrying terminal to obtain a first detection signal.

[0036] As a further technical solution of the present invention, the bushing air-end detection device detects the vibration condition of the bushing air end to obtain a second detection signal; specifically:

[0037] The current booster provides current for a bushing air-end current-carrying terminal arranged at the air end of the bushing current-carrying conductor;

[0038] A bushing air-end elastic current-carrying terminal arranged between the air end of the bushing current-carrying conductor and the bushing air-end current-carrying terminal generates mechanical vibration under the action of the current of the bushing air-end current-carrying terminal;

[0039] A second vibration sensor arranged on a second flange at the air end of the bushing current-carrying conductor detects the mechanical vibration generated by the bushing air-end elastic current-carrying terminal to obtain a second detection signal.

[0040] As a further technical solution of the present invention, the measurement and control terminal receives the first detection signal and the second detection signal, and analyzes and judges the operating state of the bushing by analyzing the first detection signal and the second detection signal, specifically including:

[0041] The measurement and control terminal samples the first detection signal and the second detection signal at a fixed frequency;

[0042] Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve;

[0043] Analyze the closed trajectory curve according to the preset judgment rules to diagnose the bushing fault.

[0044] Further, the analysis of the closed trajectory curve according to the preset judgment rules to diagnose the bushing fault is specifically:

[0045] When the closed trajectory curve is circular or elliptical, it indicates that the bushing is normal;

[0046] When the closed trajectory curve is banana-shaped or outward V-shaped, it indicates that the bushing is bent or the terminal is twisted;

[0047] When there are multiple loops or intersections in the closed trajectory curve, it indicates that the elastic current-carrying terminal has slight poor contact;

[0048] When the closed trajectory curve diverges or has local depressions, it indicates that the elastic current-carrying terminal has serious poor contact.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. Based on the principle of double-frequency excitation vibration test, the present invention uses an AC variable-frequency power supply to emit a double-frequency excitation signal, which is amplified by a current booster; the amplified current passes through the elastic current-carrying terminals on the oil side and air side of the bushing, making its distribution uneven, and then exciting mechanical vibration; the vibration sensor is responsible for collecting these mechanical vibration signals and transmitting them to the measurement and control terminal; the measurement and control terminal analyzes and processes the collected vibration signals; according to the preset judgment principle, by analyzing the shape of the vibration trajectory under different frequency layers, it is judged whether there are problems such as bending of the bushing, twisting of the terminal, and poor contact of the elastic current-carrying terminal;

[0051] 2. By setting the first flange and the second flange, it is used to fix and seal the bushing oil-end detection device and the bushing air-end detection device to ensure its normal operation.

[0052] 3. Through the frequency doubling excitation vibration test method, the present invention can detect minor faults such as casing bending, terminal block twisting, and poor contact of elastic current-carrying terminals. Compared with traditional detection methods, the detection accuracy is greatly improved. For example, in the case of slight poor contact of elastic current-carrying terminals, it may be difficult to detect by traditional methods, while the present invention can accurately judge by analyzing the vibration trajectory.

[0053] 4. The present invention can realize real-time monitoring of the operating state of the casing, timely discover potential fault hazards, avoid the further development of faults, and ensure the safe and stable operation of the power system. For example, during the operation of the casing, once poor contact of the elastic current-carrying terminal occurs, the measurement and control terminal can quickly detect and issue a warning.

[0054] 5. The entire detection process is relatively simple to operate, without complex operation procedures and professional skills. The control of equipment such as AC variable frequency power supplies and current boosters is completed by the measurement and control terminal, reducing the work difficulty and labor intensity of operators.

[0055] 6. By timely discovering and handling casing faults, power accidents caused by casing faults are reduced, and the maintenance cost and power outage loss are decreased, having significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 FIG. is a structural diagram of a device for detecting the current-carrying contact performance of a casing proposed by the present invention;

[0057] Figure 2 FIG. is a flowchart of a method for detecting the current-carrying contact performance of a casing proposed by the present invention;

[0058] As shown in the figure:

[0059] 10 - AC excitation power supply, 20 - current booster, 30 - casing oil end detection device, 40 - casing air end detection device, 50 - measurement and control terminal, 60 - casing current-carrying conductor, 70 - casing capacitance core; 301 - casing oil end current-carrying terminal, 302 - casing oil end elastic current-carrying terminal, 303 - first vibration sensor, 304 - first flange; 401 - casing air end current-carrying terminal, 402 - casing air end elastic current-carrying terminal, 403 - second vibration sensor, 404 - second flange. DETAILED DESCRIPTION OF THE INVENTION

[0060] The following describes the specific embodiments of the present invention in conjunction with the drawings and embodiments:

[0061] It should be noted that the structures, colors, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present invention. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0062] At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0063] As Figure 1 shown, the present invention provides a device for detecting the current-carrying contact performance of a bushing, including:

[0064] An AC excitation power supply 10 for generating an excitation signal;

[0065] A current booster 20 for amplifying the excitation signal generated by the AC excitation power supply;

[0066] A bushing oil-end detection device 30 for detecting the vibration condition of the bushing oil end to obtain a first detection signal;

[0067] A bushing air-end detection device 40 for detecting the vibration condition of the bushing air end to obtain a second detection signal;

[0068] A measurement and control terminal 50 for receiving the first detection signal and the second detection signal and judging the operating state of the bushing by analyzing the first detection signal and the second detection signal;

[0069] The output end of the AC excitation power supply 10 is connected to the current booster 20, the output end of the current booster 20 is connected to the bushing oil-end detection device 30 and the bushing air-end detection device 40, and the output ends of the bushing oil-end detection device 30 and the bushing air-end detection device 40 are connected to the measurement and control terminal 50.

[0070] Based on the principle of frequency-doubling excitation vibration test, the present invention uses an AC variable-frequency power supply to generate a frequency-doubling excitation signal of 100 Hz to 1000 Hz. The excitation current is amplified 100 to 10,000 times by a current booster. The amplified current passes through the elastic current-carrying terminals on the oil side and air side of the bushing, making their distribution uneven, and then exciting mechanical vibration. The vibration sensor is responsible for collecting these mechanical vibration signals and transmitting them to the measurement and control terminal. The measurement and control terminal analyzes and processes the collected vibration signals. According to the preset judgment principle, by analyzing the shape of the vibration trajectory under different frequency layers, it is judged whether there are problems such as bending of the bushing, distortion of the wiring terminal, and poor contact of the elastic current-carrying terminal.

[0071] In the embodiment of the present invention, the bushing oil-end detection device 30 includes:

[0072] The bushing oil-end current-carrying terminal 301 is arranged at the oil end of the bushing current-carrying conductor and is connected to the oil end of the bushing current-carrying conductor;

[0073] The bushing oil-end elastic current-carrying terminal 302 is arranged between the oil end of the bushing current-carrying conductor and the bushing oil-end current-carrying terminal 301 and is connected to the bushing oil-end current-carrying terminal 301 for generating mechanical vibration;

[0074] The first vibration sensor 303 is arranged on the first flange 304 at the oil end of the bushing current-carrying conductor for detecting the mechanical vibration generated by the bushing oil-end elastic current-carrying terminal 302;

[0075] The output end of the first vibration sensor 303 is connected to the measurement and control terminal 50, and the bushing oil-end current-carrying terminal 301 is connected to the output end of the current booster 20.

[0076] In the embodiment of the present invention, the bushing air-end detection device 40 includes:

[0077] The bushing air-end current-carrying terminal 401 is arranged at the air end of the bushing current-carrying conductor and is connected to the air end of the bushing current-carrying conductor;

[0078] The bushing air-end elastic current-carrying terminal 402 is arranged between the air end of the bushing current-carrying conductor and the bushing air-end current-carrying terminal 401 and is connected to the bushing air-end current-carrying terminal 401 for generating mechanical vibration;

[0079] The second vibration sensor 403 is arranged on the second flange 404 at the air end of the bushing current-carrying conductor for detecting the mechanical vibration generated by the bushing air-end elastic current-carrying terminal 402;

[0080] The output end of the second vibration sensor 403 is connected to the measurement and control terminal 50, and the bushing air-end current-carrying terminal 301 is connected to the output end of the current booster 20.

[0081] In the embodiment of the present invention, the current booster receives the current of the AC variable-frequency power supply, amplifies the excitation voltage generated by the AC variable-frequency power supply by 100 to 10,000 times to meet the current intensity required for detection; the turns ratio is 220:5, and the 1h thermal stable current is 3,000 A. The heat dissipation method of the current booster is liquid immersion type or dry type. The current booster outputs the amplified current to the elastic current-carrying terminal of the bushing and communicates with the measurement and control terminal to receive monitoring and control to ensure normal operation.

[0082] Among them, the AC variable-frequency power supply is used to generate a variable-frequency excitation signal of 50 Hz - 1000 Hz, providing an excitation source for the entire detection process. The rated output power is 1600 VA, and the 1h thermal stable current is 3,000 A. The heat dissipation method of the AC variable-frequency power supply is liquid immersion type or dry type. It is connected to the current booster to provide input current for it and receives the control signal of the measurement and control terminal, and adjusts the output frequency and power according to the control instruction. The AC variable-frequency power supply can accurately set the excitation frequency to ensure the stability and accuracy of the excitation signal, providing a reliable excitation source for subsequent detection.

[0083] In the embodiment of the present invention, a bushing capacitor core 70 is arranged outside the bushing current-carrying conductor 60. The bushing capacitor core is a key component of the bushing and plays an important role in current transmission and electric field distribution. The two ends of the bushing current-carrying conductor are respectively the bushing current-carrying conductor oil end and the bushing current-carrying conductor air end. A first flange is arranged outside the bushing current-carrying conductor oil end for fixing and sealing the bushing oil side part to ensure its normal operation. A bushing oil side current-carrying terminal is arranged at the bushing current-carrying conductor oil end, and a bushing oil side elastic current-carrying terminal is also arranged between the bushing oil side current-carrying terminal and the bushing current-carrying conductor; the bushing oil side elastic current-carrying terminal receives the amplified excitation current and generates mechanical vibration under the action of the current, and its vibration state reflects the operation condition of the bushing oil side. The bushing oil side current-carrying terminal connects the bushing oil side elastic current-carrying terminal with other circuit parts to transmit current.

[0084] A second flange is arranged outside the bushing current-carrying conductor air end, which is similar to the function of the end face flange on the bushing oil side, for fixing and sealing the bushing air side part; a bushing air side current-carrying terminal is arranged at the bushing current-carrying conductor air end, and a bushing air side elastic current-carrying terminal is also arranged between the bushing air side current-carrying terminal and the bushing current-carrying conductor; the bushing air side elastic current-carrying terminal is similar to the bushing oil side elastic current-carrying terminal, receiving current and generating vibration for detecting the condition of the bushing air side. The bushing air side current-carrying terminal connects the bushing air side elastic current-carrying terminal with the external circuit to achieve current transmission.

[0085] In the embodiments of the present invention, a first vibration sensor and a second vibration sensor are respectively arranged on the first flange and the second flange; the vibration signals can be accurately collected to avoid signal distortion. The output ends of the first vibration sensor and the second vibration sensor are connected to the measurement and control terminal. The current-carrying terminal on the oil side of the bushing and the current-carrying terminal on the air side of the bushing are connected to the current booster, and the current booster is connected to the output end of the AC variable-frequency power supply. The first vibration sensor and the second vibration sensor are used to collect the mechanical vibration signals generated by the elastic current-carrying terminal at the oil end of the bushing and the elastic current-carrying terminal at the air end of the bushing. The ±1dB frequency band range is 10 - 1000Hz, the measurement range is 0 - 20mm / s, the ±3dB frequency band range is 0.5 - 10kHz, and the sensitivity is 100mV / g.

[0086] The measurement and control terminal is responsible for controlling and monitoring the entire detection process, receiving the signals of the vibration sensors for analysis and processing, and simultaneously sending control commands to the AC variable-frequency power supply and the current booster. The measurement frequency band is not less than 100MHz, the range is ±20V, the storage depth is 128MS, the frequency adjustment accuracy is 1Hz, and the current adjustment accuracy is 10A. The measurement and control terminal ensures the stability and accuracy of signal transmission, avoiding signal loss or interference.

[0087] See Figure 2 , the present invention also provides a method for detecting the current-carrying contact performance of a bushing, including:

[0088] Step S1, the AC excitation power supply generates an excitation signal;

[0089] Step S2, the current booster amplifies the excitation signal generated by the AC excitation power supply;

[0090] Step S3, the detection device at the oil end of the bushing detects the vibration condition of the oil end of the bushing to obtain a first detection signal;

[0091] Step S4, the detection device at the air end of the bushing detects the vibration condition of the air end of the bushing to obtain a second detection signal;

[0092] Step S5, the measurement and control terminal receives the first detection signal and the second detection signal, and judges the operating state of the bushing by analyzing the first detection signal and the second detection signal.

[0093] In step S3, the detection device at the oil end of the bushing detects the vibration condition of the oil end of the bushing to obtain a first detection signal; specifically:

[0094] The current booster provides current for the current-carrying terminal at the oil end of the bushing conductor of the bushing;

[0095] The elastic current-carrying terminal at the oil end of the bushing conductor, which is arranged between the oil end of the bushing conductor and the current-carrying terminal at the oil end of the bushing, generates mechanical vibration under the action of the current of the current-carrying terminal at the oil end of the bushing.

[0096] The first vibration sensor disposed on the first flange at the oil end of the bushing current-carrying conductor detects the mechanical vibration generated by the elastic current-carrying terminal at the oil end of the bushing to obtain a first detection signal.

[0097] In step S4, the bushing air-end detection device detects the vibration condition of the bushing air end to obtain a second detection signal; specifically:

[0098] The current booster provides current for the bushing air-end current-carrying terminal disposed at the air end of the bushing current-carrying conductor.

[0099] The elastic current-carrying terminal at the bushing air end disposed between the air end of the bushing current-carrying conductor and the bushing air-end current-carrying terminal generates mechanical vibration under the action of the current of the bushing air-end current-carrying terminal.

[0100] The second vibration sensor disposed on the second flange at the air end of the bushing current-carrying conductor detects the mechanical vibration generated by the elastic current-carrying terminal at the bushing air end to obtain a second detection signal.

[0101] In step S5, the measurement and control terminal receives the first detection signal and the second detection signal, and judges the operating state of the bushing by analyzing the first detection signal and the second detection signal, specifically including:

[0102] The measurement and control terminal samples the first detection signal and the second detection signal at a fixed frequency.

[0103] Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve.

[0104] Analyze the closed trajectory curve according to the preset judgment rules to diagnose the bushing fault.

[0105] Sample for a fixed time at a frequency. At each frequency f, sample for a fixed time t0, and then construct a coordinate system with the horizontal direction as the x-axis and the vertical direction as the y-axis. The sampling time t0 ensures that sufficient vibration information is obtained without increasing the amount of data processing too much; the construction of the coordinate system should be accurate to ensure that the subsequent drawn trajectory curve can truly reflect the vibration condition.

[0106] Draw a closed trajectory curve: Take the (x(t), y(t)) corresponding to each moment as a coordinate point and connect them in sequence to form a closed trajectory curve. The key is to ensure the accuracy of the coordinate points and the correctness of the connection order, so that the trajectory curve can accurately reflect the change law of the vibration.

[0107] Among them, analyzing the closed trajectory curve according to the preset judgment rules to diagnose the bushing fault, specifically:

[0108] When the closed trajectory curve is circular or elliptical, it indicates that the bushing is normal;

[0109] When the closed trajectory curve is banana-shaped or outward splayed, it indicates that the bushing is bent or the terminal block is distorted;

[0110] When the closed trajectory curve has multiple loops or intersections, it indicates that the elastic current-carrying terminal has slight poor contact;

[0111] When the closed trajectory curve diverges or has local depressions, it indicates that the elastic current-carrying terminal has serious poor contact.

[0112] The present invention accurately identifies the trajectory shape and conducts fault diagnosis according to the judgment principle to ensure the reliability of the diagnosis result.

[0113] The present invention can detect minor faults such as bushing bending, terminal block distortion, and poor contact of elastic current-carrying terminals through the method of frequency-doubling excitation vibration test. Compared with traditional detection methods, the detection accuracy is greatly improved. For example, in the case of slight poor contact of elastic current-carrying terminals, it may be difficult to detect with traditional methods, while the present invention can accurately judge by analyzing the vibration trajectory.

[0114] The invention can realize real-time monitoring of the operating state of the bushing, timely discover potential fault hazards, avoid the further development of faults, and ensure the safe and stable operation of the power system. For example, during the operation of the bushing, once poor contact of the elastic current-carrying terminal occurs, the measurement and control terminal can quickly detect it and issue a warning.

[0115] The entire detection process is relatively simple to operate and does not require complex operation procedures and professional skills. The control of equipment such as AC variable-frequency power supplies and current boosters is completed by the measurement and control terminal, reducing the work difficulty and labor intensity of operators.

[0116] By timely discovering and handling bushing faults, power accidents caused by bushing faults are reduced, and the maintenance cost and power outage loss are lowered, having significant economic and social benefits.

[0117] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for detecting the current-carrying contact performance of a bushing, characterized in that: include: AC excitation power supply, used to generate an excitation signal; A current booster, used to amplify the excitation signal generated by the AC excitation power supply; The casing oil end detection device is used to detect the vibration of the casing oil end to obtain a first detection signal; The casing air end detection device is used to detect the vibration of the casing air end to obtain a second detection signal; A measurement and control terminal, used for receiving the first detection signal and the second detection signal, and determining the running state of the casing by analyzing the first detection signal and the second detection signal; The output end of the AC excitation power supply is connected to the current booster, the output end of the current booster is connected to the casing oil end detection device and the casing air end detection device, and the output ends of the casing oil end detection device and the casing air end detection device are connected to the measurement and control terminal.

2. A device for detecting current-carrying contact performance of a bushing according to claim 1, characterized in that: The casing oil end detection device comprises: The casing oil end current-carrying terminal is arranged at the casing current-carrying conductor oil end and connected to the casing current-carrying conductor oil end; The bushing oil end elastic current-carrying terminal is arranged between the bushing current-carrying conductor oil end and the bushing oil end current-carrying terminal and is connected to the bushing oil end current-carrying terminal for generating mechanical vibration; A first vibration sensor is arranged on a first flange at the oil end of the current-carrying conductor of the bushing and is used to detect the mechanical vibration generated by the elastic current-carrying terminal at the oil end of the bushing; The output end of the first vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal of the casing oil end is connected to the output end of the current booster.

3. A device for detecting current-carrying contact performance of a bushing according to claim 1, characterized in that: The casing air end detection device comprises: The bushing air end current-carrying terminal is arranged at the bushing current-carrying conductor air end and connected to the bushing current-carrying conductor air end; The bushing air end elastic current-carrying terminal is arranged between the bushing current-carrying conductor air end and the bushing air end current-carrying terminal and connected to the bushing air end current-carrying terminal for generating mechanical vibration; A second vibration sensor is disposed on a second flange at the air end of the current-carrying conductor of the bushing and is used to detect mechanical vibrations generated by the elastic current-carrying terminal at the air end of the bushing; The output end of the second vibration sensor is connected to the measurement and control terminal, and the current-carrying terminal of the air end of the bushing is connected to the output end of the current booster.

4. A device for detecting current-carrying contact performance of a bushing according to claim 1, characterized in that: The current booster is used to amplify the excitation voltage generated by the AC variable frequency power supply by 100 to 10,000 times, with a transformation ratio of 220:5 and a 1h thermal stability current of 3000A. The heat dissipation method of the current booster is liquid immersion or dry.

5. The device for detecting the current-carrying contact performance of a bushing according to claim 1, characterized in that: The AC variable frequency power supply is used to generate a variable frequency excitation signal of 50Hz-1000Hz, with a rated output power of 1600VA and a 1h thermal stability current of 3000A. The heat dissipation method of the AC variable frequency power supply is liquid immersion or dry type.

6. A method for detecting the current-carrying contact performance of a bushing, characterized in that: A device for detecting current-carrying contact performance of a bushing as claimed in any one of claims 1 to 5 is used, comprising the following steps: The AC excitation power supply generates an excitation signal; The current booster amplifies the excitation signal generated by the AC excitation power supply; The casing oil end detection device detects the vibration condition of the casing oil end to obtain a first detection signal; The casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; The measurement and control terminal receives the first detection signal and the second detection signal, and determines the operating state of the casing by analyzing the first detection signal and the second detection signal.

7. A method for detecting current-carrying contact performance of a bushing according to claim 6, characterized in that: The casing oil end detection device detects the vibration of the casing oil end to obtain a first detection signal; specifically: The current booster provides current to the bushing oil end current carrying terminal arranged at the oil end of the bushing current carrying conductor; The elastic current-carrying terminal at the oil end of the bushing, which is arranged between the oil end of the current-carrying conductor of the bushing and the current-carrying terminal at the oil end of the bushing, generates mechanical vibration under the action of the current at the current-carrying terminal at the oil end of the bushing; A first vibration sensor disposed on a first flange at the oil end of the current-carrying conductor of the bushing detects mechanical vibration generated by an elastic current-carrying terminal at the oil end of the bushing to obtain a first detection signal.

8. A method for detecting current-carrying contact performance of a bushing according to claim 6, characterized in that: The casing air end detection device detects the vibration of the casing air end to obtain a second detection signal; specifically: The current booster provides current to the bushing air end current-carrying terminal arranged at the air end of the bushing current-carrying conductor; The elastic current-carrying terminal of the bushing air end, which is arranged between the air end of the bushing current-carrying conductor and the current-carrying terminal of the bushing air end, generates mechanical vibration under the action of the current of the current-carrying terminal of the bushing air end; The second vibration sensor arranged on the second flange of the air end of the bushing current-carrying conductor detects the mechanical vibration generated by the elastic current-carrying terminal of the bushing air end to obtain a second detection signal.

9. A method for detecting current-carrying contact performance of a bushing according to claim 6, characterized in that: The measurement and control terminal receives the first detection signal and the second detection signal, and determines the running state of the casing by analyzing the first detection signal and the second detection signal, specifically including: The measurement and control terminal performs fixed frequency sampling on the first detection signal and the second detection signal; Connect the coordinate points corresponding to each sampling moment in sequence to draw a closed trajectory curve; The closed trajectory curve is analyzed according to the preset judgment rules and the casing fault is diagnosed.

10. A method for detecting current-carrying contact performance of a bushing according to claim 9, characterized in that: The closed trajectory curve is analyzed according to the preset judgment rules to diagnose the casing fault, specifically: When the closed trajectory curve is circular or elliptical, it indicates that the casing is normal; When the closed trajectory curve is banana-shaped or outward-splayed, it indicates that the bushing is bent or the terminal is twisted; When the closed trajectory curve has multiple loops or intersects, it indicates that the elastic current-carrying terminal has a slight poor contact; When the closed trajectory curve trajectory diverges and is partially concave, it indicates that the elastic current-carrying terminal has serious poor contact.

Images